1 /*
2 * Copyright (c) 2021, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/cds_globals.hpp"
26 #include "cds/classListParser.hpp"
27 #include "cds/classListWriter.hpp"
28 #include "cds/lambdaFormInvokers.inline.hpp"
29 #include "classfile/classFileStream.hpp"
30 #include "classfile/classLoader.hpp"
31 #include "classfile/classLoaderData.hpp"
32 #include "classfile/classLoaderDataGraph.hpp"
33 #include "classfile/moduleEntry.hpp"
34 #include "classfile/symbolTable.hpp"
35 #include "classfile/systemDictionaryShared.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "oops/constantPool.inline.hpp"
38 #include "oops/instanceKlass.hpp"
39 #include "runtime/javaCalls.hpp"
40 #include "runtime/mutexLocker.hpp"
41
42 fileStream* ClassListWriter::_classlist_file = nullptr;
43
44 void ClassListWriter::init() {
45 // For -XX:DumpLoadedClassList=<file> option
46 if (DumpLoadedClassList != nullptr) {
47 const char* list_name = make_log_name(DumpLoadedClassList, nullptr);
48 _classlist_file = new(mtInternal)
49 fileStream(list_name);
50 _classlist_file->print_cr("# NOTE: Do not modify this file.");
51 _classlist_file->print_cr("#");
52 _classlist_file->print_cr("# This file is generated via the -XX:DumpLoadedClassList=<class_list_file> option");
53 _classlist_file->print_cr("# and is used at CDS archive dump time (see -Xshare:dump).");
54 _classlist_file->print_cr("#");
55 FREE_C_HEAP_ARRAY(char, list_name);
56 }
57 }
58
59 void ClassListWriter::write(const InstanceKlass* k, const ClassFileStream* cfs) {
60 assert(is_enabled(), "must be");
61
62 if (!ClassLoader::has_jrt_entry()) {
63 log_warning(aot)("DumpLoadedClassList and CDS are not supported in exploded build");
64 DumpLoadedClassList = nullptr;
65 return;
66 }
67
68 ClassListWriter w;
69 write_to_stream(k, w.stream(), cfs);
70 }
71
72 class ClassListWriter::IDTable : public HashTable<
73 const InstanceKlass*, int,
74 15889, // prime number
75 AnyObj::C_HEAP> {};
76
77 ClassListWriter::IDTable* ClassListWriter::_id_table = nullptr;
78 int ClassListWriter::_total_ids = 0;
79
80 int ClassListWriter::get_id(const InstanceKlass* k) {
81 assert_locked();
82 if (_id_table == nullptr) {
83 _id_table = new (mtClass)IDTable();
84 }
85 bool created;
86 int* v = _id_table->put_if_absent(k, &created);
87 if (created) {
88 *v = _total_ids++;
89 }
90 return *v;
91 }
92
93 bool ClassListWriter::has_id(const InstanceKlass* k) {
94 assert_locked();
95 if (_id_table != nullptr) {
96 return _id_table->get(k) != nullptr;
97 } else {
98 return false;
99 }
100 }
101
102 void ClassListWriter::handle_class_unloading(const InstanceKlass* klass) {
103 assert_locked();
104 if (_id_table != nullptr) {
105 _id_table->remove(klass);
106 }
107 }
108
109 void ClassListWriter::write_to_stream(const InstanceKlass* k, outputStream* stream, const ClassFileStream* cfs) {
110 assert_locked();
111
112 ClassLoaderData* loader_data = k->class_loader_data();
113 bool is_builtin_loader = SystemDictionaryShared::is_builtin_loader(loader_data);
114 if (!is_builtin_loader) {
115 // class may be loaded from shared archive
116 if (!k->in_aot_cache()) {
117 if (cfs == nullptr || cfs->source() == nullptr) {
118 // CDS static dump only handles unregistered class with known source.
119 return;
120 }
121 if (strncmp(cfs->source(), "file:", 5) != 0) {
122 return;
123 }
124 } else {
125 // Shared unregistered classes are skipped since their real source are not recorded in shared space.
126 return;
127 }
128 if (!SystemDictionaryShared::add_unregistered_class(Thread::current(), (InstanceKlass*)k)) {
129 return;
130 }
131 }
132
133 if (cfs != nullptr && cfs->source() != nullptr) {
134 if (strcmp(cfs->source(), "_ClassSpecializer_generateConcreteSpeciesCode") == 0) {
135 return;
136 }
137
138 if (strncmp(cfs->source(), "__", 2) == 0) {
139 // generated class: __dynamic_proxy__, __JVM_LookupDefineClass__, etc
140 return;
141 }
142 }
143
144 {
145 InstanceKlass* super = k->super();
146 if (super != nullptr && !has_id(super)) {
147 return;
148 }
149
150 Array<InstanceKlass*>* interfaces = k->local_interfaces();
151 int len = interfaces->length();
152 for (int i = 0; i < len; i++) {
153 InstanceKlass* intf = interfaces->at(i);
154 if (!has_id(intf)) {
155 return;
156 }
157 }
158 }
159
160 if (k->is_hidden()) {
161 return;
162 }
163
164 if (k->module()->is_patched()) {
165 return;
166 }
167
168 ResourceMark rm;
169 stream->print("%s id: %d", k->name()->as_C_string(), get_id(k));
170 if (!is_builtin_loader) {
171 InstanceKlass* super = k->super();
172 assert(super != nullptr, "must be");
173 stream->print(" super: %d", get_id(super));
174
175 Array<InstanceKlass*>* interfaces = k->local_interfaces();
176 int len = interfaces->length();
177 if (len > 0) {
178 stream->print(" interfaces:");
179 for (int i = 0; i < len; i++) {
180 InstanceKlass* intf = interfaces->at(i);
181 stream->print(" %d", get_id(intf));
182 }
183 }
184
185 // NB: the string following "source: " is not really a proper file name, but rather
186 // a truncated URI referring to a file. It must be decoded after reading.
187 #ifdef _WINDOWS
188 // "file:/C:/dir/foo.jar" -> "C:/dir/foo.jar"
189 stream->print(" source: %s", cfs->source() + 6);
190 #else
191 // "file:/dir/foo.jar" -> "/dir/foo.jar"
192 stream->print(" source: %s", cfs->source() + 5);
193 #endif
194 }
195
196 stream->cr();
197 stream->flush();
198 }
199
200 void ClassListWriter::delete_classlist() {
201 if (_classlist_file != nullptr) {
202 delete _classlist_file;
203 }
204 }
205
206 class ClassListWriter::WriteResolveConstantsCLDClosure : public CLDClosure {
207 public:
208 void do_cld(ClassLoaderData* cld) {
209 for (Klass* klass = cld->klasses(); klass != nullptr; klass = klass->next_link()) {
210 if (klass->is_instance_klass()) {
211 InstanceKlass* ik = InstanceKlass::cast(klass);
212 write_resolved_constants_for(ik);
213 }
214 }
215 }
216 };
217
218 void ClassListWriter::write_resolved_constants() {
219 if (!is_enabled()) {
220 return;
221 }
222 MutexLocker lock(ClassLoaderDataGraph_lock);
223 MutexLocker lock2(ClassListFile_lock, Mutex::_no_safepoint_check_flag);
224
225 WriteResolveConstantsCLDClosure closure;
226 ClassLoaderDataGraph::loaded_cld_do(&closure);
227 }
228
229 void ClassListWriter::write_resolved_constants_for(InstanceKlass* ik) {
230 if (!SystemDictionaryShared::is_builtin_loader(ik->class_loader_data()) ||
231 ik->is_hidden()) {
232 return;
233 }
234 if (LambdaFormInvokers::may_be_regenerated_class(ik->name())) {
235 return;
236 }
237 if (ik->name()->equals("jdk/internal/module/SystemModules$all")) {
238 // This class is regenerated during JDK build process, so the classlist
239 // may not match the version that's in the real jdk image.
240 return;
241 }
242
243 if (!has_id(ik)) { // do not resolve CP for classes loaded by custom loaders.
244 return;
245 }
246
247 ResourceMark rm;
248 ConstantPool* cp = ik->constants();
249 GrowableArray<bool> list(cp->length(), cp->length(), false);
250 bool print = false;
251
252 for (int cp_index = 1; cp_index < cp->length(); cp_index++) { // Index 0 is unused
253 switch (cp->tag_at(cp_index).value()) {
254 case JVM_CONSTANT_Class:
255 {
256 Klass* k = cp->resolved_klass_at(cp_index);
257 if (k->is_instance_klass()) {
258 list.at_put(cp_index, true);
259 print = true;
260 }
261 }
262 break;
263 }
264 }
265
266 if (cp->cache() != nullptr) {
267 Array<ResolvedIndyEntry>* indy_entries = cp->cache()->resolved_indy_entries();
268 if (indy_entries != nullptr) {
269 for (int i = 0; i < indy_entries->length(); i++) {
270 ResolvedIndyEntry* rie = indy_entries->adr_at(i);
271 int cp_index = rie->constant_pool_index();
272 if (rie->is_resolved()) {
273 list.at_put(cp_index, true);
274 print = true;
275 }
276 }
277 }
278
279 Array<ResolvedFieldEntry>* field_entries = cp->cache()->resolved_field_entries();
280 if (field_entries != nullptr) {
281 for (int i = 0; i < field_entries->length(); i++) {
282 ResolvedFieldEntry* rfe = field_entries->adr_at(i);
283 if (rfe->is_resolved(Bytecodes::_getstatic) ||
284 rfe->is_resolved(Bytecodes::_putstatic) ||
285 rfe->is_resolved(Bytecodes::_getfield) ||
286 rfe->is_resolved(Bytecodes::_putfield)) {
287 list.at_put(rfe->constant_pool_index(), true);
288 print = true;
289 }
290 }
291 }
292
293 Array<ResolvedMethodEntry>* method_entries = cp->cache()->resolved_method_entries();
294 if (method_entries != nullptr) {
295 for (int i = 0; i < method_entries->length(); i++) {
296 ResolvedMethodEntry* rme = method_entries->adr_at(i);
297 if (rme->is_resolved(Bytecodes::_invokevirtual) ||
298 rme->is_resolved(Bytecodes::_invokespecial) ||
299 rme->is_resolved(Bytecodes::_invokeinterface) ||
300 rme->is_resolved(Bytecodes::_invokestatic) ||
301 rme->is_resolved(Bytecodes::_invokehandle)) {
302 list.at_put(rme->constant_pool_index(), true);
303 print = true;
304 }
305 }
306 }
307 }
308
309 if (print) {
310 outputStream* stream = _classlist_file;
311 stream->print("@cp %s", ik->name()->as_C_string());
312 for (int i = 0; i < list.length(); i++) {
313 if (list.at(i)) {
314 constantTag cp_tag = cp->tag_at(i).value();
315 assert(cp_tag.value() == JVM_CONSTANT_Class ||
316 cp_tag.value() == JVM_CONSTANT_Fieldref ||
317 cp_tag.value() == JVM_CONSTANT_Methodref||
318 cp_tag.value() == JVM_CONSTANT_InterfaceMethodref ||
319 cp_tag.value() == JVM_CONSTANT_InvokeDynamic, "sanity");
320 stream->print(" %d", i);
321 }
322 }
323 stream->cr();
324 }
325 }
326
327 void ClassListWriter::write_loader_negative_lookup_cache_for(oop loader, const char* loader_type) {
328 TempNewSymbol method = SymbolTable::new_symbol("negativeLookupCacheContents");
329 TempNewSymbol signature = SymbolTable::new_symbol("()Ljava/lang/String;");
330
331 EXCEPTION_MARK;
332 HandleMark hm(THREAD);
333
334 JavaValue result(T_OBJECT);
335 JavaCalls::call_virtual(&result,
336 Handle(THREAD, loader),
337 loader->klass(),
338 method,
339 signature,
340 CHECK);
341
342 if (HAS_PENDING_EXCEPTION) {
343 log_warning(cds)("Error during BuiltinClassLoader::negativeLookupCacheContents() call for %s loader", loader_type);
344 CLEAR_PENDING_EXCEPTION;
345 return;
346 } else if (result.get_oop() == nullptr) {
347 return;
348 }
349
350 ResourceMark rm;
351 const char* cache_contents = java_lang_String::as_utf8_string(result.get_oop());
352 log_debug(cds)("%s loader negative cache: %s", loader_type, cache_contents);
353
354 outputStream* stream = _classlist_file;
355 const size_t buffer_size = strlen(ClassListParser::LOADER_NEGATIVE_CACHE_TAG) + 1 /* for space*/
356 + strlen(loader_type) + 1 /* for space */ + strlen(cache_contents) + 1 /* for null character */;
357 char* buffer = NEW_C_HEAP_ARRAY(char, buffer_size, mtInternal);
358 _classlist_file->set_scratch_buffer(buffer, buffer_size);
359 MutexLocker lock2(ClassListFile_lock, Mutex::_no_safepoint_check_flag);
360 stream->print("%s %s %s", ClassListParser::LOADER_NEGATIVE_CACHE_TAG, loader_type, cache_contents);
361 stream->cr();
362 _classlist_file->set_scratch_buffer(nullptr, 0);
363 }
364
365 void ClassListWriter::write_loader_negative_lookup_cache() {
366 if (!is_enabled()) {
367 return;
368 }
369
370 write_loader_negative_lookup_cache_for(SystemDictionary::java_platform_loader(), "platform");
371 write_loader_negative_lookup_cache_for(SystemDictionary::java_system_loader(), "app");
372 }